Method and apparatus for protecting wells



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ATTORNEY- United States Patent 3,156,300 METHOD AND APPARATUS FGRPROTECTHNG WELLS John S. Page and John S. Page, Jr., both of 1450 ElMirador Ave, Long Beach, Calif. Filed Aug. 14, 1963, Ser. No. 302,073 29Claims. (Cl. 166-665) This application is a continuation-in-part of ourcopending application Serial No. 450,884, filed August 19, 1954, nowabandoned.

This invention relates to the protection of producing wells,particularly oil wells situated in bodies of water, to prevent loss ofthe products of such wells in event the upper portions thereof aresubjected to damaging forces.

In wells located in the waters of gulfs, lakes and oceans, the platformsabove the surface of the Water and the casings between the platforms andthe submerged land are vulnerable to breakage or rupture by collisionwith ships or other vessels, especially in stormy weather.

It is known that flowing wells located in bodies of water have sufferedconsiderable loss of the valuable products thereof as a result of ships,barges, or floating objects colliding with the platforms and rupturingthe exposed vulnerable portions of the casing or flow lines connectedtherewith at the top of the well.

Accordingly, it is the primary object of the present invention toprovide a novel method and means for automatically shutting off the flowof a well such as described, at a safe distance below the Vulnerableparts of the well incident to the platform or other parts at the top ofthe well or adjacent the top of the well, being accidentally subjectedto forces which are likely to rupture or will rupture the vulnerableparts.

It is another object of this invention to provide a novel method ofprotecting a well of the character described in a manner such that theshutting off of the flow at a safe distance below the vulnerable part ofthe casing and flow lines, will take place before the forces sustainedthereby become effective to rupture such parts.

Another object of the invention is to provide means and a method forprotecting a well for the purpose described, by utilizing valve meansactuated by fluid pressure in the well to automatically shut off theflow in the well at a safe distance below the vulnerable parts at thetop of the well or adjacent the top of the well, incident to thesevulnerable parts sustaining a shock or impact of such severity as wouldtend to rupture them and consequently cause an uncontrolled flow of thewell.

Another object of this invention is to provide a shut-off tool forprotecting a well in the manner described, wherein valve means forshutting off the Well is actuated by the fluid pressure in the well tomaintain normal production in such a manner that incident to theplatform or adjacent parts of the well sustaining a collision shock or asimilar shock of a severity which would rupture such vulnerable parts,the valve means will also be actuated by the fluid pressure in the wellto shut off the flow at a safe distance below said vulnerable partsprior to the rupturing thereof.

It is another object hereof to provide a novel trigger means whichoperates the valve means to shut off the flow below the parts of thewell susceptible to rupturing, incident to the initial application tothe trigger means of a severe collision shock or a similar forcetransmitted through the well platform or associated elements at the topof the well, thereby shutting off the well before such forces becomeeffective to rupture the casing and associated flow lines at the top ofthe well.

An additional object hereof is to provide a shut-off tool such asdescribed which readily may be positioned "ice in a well on a tubingstring so as to be subject to operation responsive to trigger means atthe top of the well or manually controlled from the top of the Well.

A further object hereof is to provide a shut-off tool such as describedwhich includes a retrievable valve unit arranged so that it may bedetached from the tool by the application to the tool from the top ofthe well, of fluid pressure in excess of the normal pressure of thewell, whereby the unit readily may be raised for inspection orreplacement of parts as required and as readily replaced on the tool.

Another object hereof is to provide a tool such as described wherein anovel sleeve valve for controlling the flow to the top of the well ishydraulically balanced by the fluid pressure in the well during flow ofthe well and remains open as long as the Valve is hydraulicallybalanced, but will move to closed position and shut off flow at the toolresponsive to fluid pressure in the well when the balancing fluidpressure on one side thereof is relieved.

It is a further object hereof to provide a tool such as describedwherein trigger means at the top of the well will respond to severecollision shocks or like impacts against the platform and associatedvulnerable element of the well, to vent to the atmosphere the fluidpressure causing the valve to be hydraulically balanced, whereby fluidpressure in the Well Will be effective to close the valve and shut offflow to the top of the well.

An additional object of the invention is the provision of a novelpressure relief valve which is actuated by the trigger means to vent tothe atmosphere the fluid pressure balancing the shut-off valve as wellas to maintain the fluid pressure in the well against the shut-offvalve, whereby the latter will be moved to closed position to shut-offflow to the top of the well.

It is another object hereof to provide a shut-off tool of the characterdescribed wherein a novel hydraulically operated anchoring means isactuated to securely anchor the tool to the casing of the well incidentto the venting to the atmosphere of the fluid pressure which providesfor hydraulically balancing the shut-off valve.

Still another object of the invention is to provide a fluid pressureoperated and controlled sub-surface shut-off valve for use in flowingwells, wherein, responsive to the application of fluid pressure to firstand second surfaces of a movable valve member and under the control ofmeans at the top of the well for controlling the application of fluidpressure to the first of said surfaces, the valve will be permitted toclose.

This invention possesses many other advantages and has other objectswhich may be made more easily apparent from a consideration of oneembodiment of the invention. For this purpose there are shown a numberof forms in the drawings accompanying and forming part of the presentspecification. These forms will now be described in detail, illustratingthe general principles of the invention, but it is to be understood thatthis detailed description is not to be taken in a limiting sense, sincethe scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIG. 1 is a schematic view of means embodying the present invention asinstalled on a Well situated in a body of water;

FIG. la is a cross sectional view taken on the line 1alm' of FIG. 1.

FIG. 1b is an enlarged vertical sectional view of the trigger valve atthe top of the well;

FIG. 2 is a fragmentary vertical sectional view of the upper part of aretrievable shut-off tool embodying this invention, as operativelyassociated with the casing and tubing string of a well such as shown inFIG. 1;

FIG. 2a is a continuation view of FIG. 2, showing the lower part of theshut-off tool;

FIG. 2b is an enlarged sectional view taken on the line 2b-2b of FIG.2a;

FIG. 3 is an enlar ed sectional view of the valve unit in the portion ofthe tool shown in FIG. 2 with the valve open;

FIG. 4 is a fragmentary vertical sectional view, partly in elevation, ofthe valve unit shown in FIG. 3, with the valve closed;

FIG. 5 is an enlarged fragmentary vertical sectional view of the valveunit as it would appear when released and ready to be retrieved;

FIG. 6 is a cross sectional view, taken on the line 6-6 of FIG. 4;

FIG. 7 is a sectional view, similar to FIG. modified form of the presentinvention;

FIG. 7a is a continuation view of FIG. 7, showing the lower part of thetool shown in FIG. 7;

FIG. 8 is an enlarged fragmentary view of the valve unit shown in FIG.7, with the valve open;

FIG. 9 is an enlarged fragmentary vertical sectional view, partly inelevation, of the valve unit shown in FIG. 8, with the valve closed;

FIG. 10 is an enlarged fragmentary sectional view of the valve unitshown in FIG. 8 as released and ready to be retrieved;

FIG. 11 is a cross sectional view taken on the line 1111 of FIG. 8;

FIG. 12 is a fragmentary sectional view, partly in elevation, of amodified form of packer setting means; and

FIG. 13 is a fragmentary sectional view taken on the line 13-13 of FIG.3.

In accordance with one embodiment of this invention, a tool mounted on atubing string as a section thereof and including anchoring means,packing means and an especially constructed shut-off valve unit, is runinto the casing of a well to be protected, for example an oil well ofthe flowing type situated in a body of water.

The tool is then anchored to the casing and the packing means set toform a seal between the tool and the casing whereby the tool is anchoredat a point for operation, for example, 100 or more feet below thesurface of the submerged land.

A pipe line connected with the valve unit in the tool is lowered withthe tool into the Well casing so that fluid under pressure from the topof the well may be applied to and vented from the valve unit in a mannerto be hereinafter described.

After anchoring the tool in the casing, that portion of the tubingstring extending upwardly from the upper end of the tool, is removexlfrom the well and a tubing plug is lowered into the well to close theupper end of the tool.

The tool provides port means below the plug whereby well fluid may flowinto the casing and thence to the top of the well through the casing.

The shut-off valve unit includes a normally open sleeve valve above thepacking means and which is axially movable to close the port meansthrough which the flow passes from the tool into the casing. Theinterior of this sleeve valve is exposed to well pressure within thetubing string. The exterior of this valve is arranged to be exposed topressure derived from the well and introduced into an annular chamber inthe tool through the pipe line eading down from its connection with thecasing head which clearly balances the hydraulic forces on the valve.Spring means is associated with the sleeve valve to hold it in openposition permitting flow to the top of the well.

The arrangement of the sleeve valve, annular chamber, and spring meansis such that when equal fluid pressures are created interiorly andexteriorly of the valve, the spring means will maintain the sleeve valvein open position. However, if the fluid pressure exposed to the exteriorof the valve in the annular chamber is vented to the atmosphere, thewell pressure interiorly of the valve instantly becomes effective tomove the valve into position to close the port means and thus shut theflow from the tool into the casing.

It is intended that this venting of pressure and consequent shutting olfof the flow at the tool take place responsive to the Well platform orother vulnerable parts of the well being subjected to blows or forces ofsuch severity as would rupture the exposed part of the casing or flowlines connected thereto, such damaging action being likely as a resultof collision with the well structure, of ships or floating or windblownobjects in stormy weather.

It is also intended that this automatic shut-off of the well take placebefore the casing or flow lines at the top of the well become rupturedand permits of wasteful uncontrolled flow of the well. This is desiredas the well pressure is depended upon to close the shut-off valve.

Accordingly, trigger means including a pressure actuated trigger valve,are provided at the top of the well to respond to the aforementionedsevere collision shocks and similar shocks, so that the fluid pressurewhich is transmitted from the top of the casing to the annular chamberaround the shut-off valve in the tool, will be vented to the atmospherewhile the trigger valve shuts off communication between the casing andthe pipe line leading to the annular chamber, thereby permitting theshut-off valve to respond to the Well pressure trapped in the tool andthus shut off the fiow at the tool.

As it may be desirable to remove the shut-off valve unit from the toolfor inspection and replacement of parts thereof, provision is made forthis removal. Accordingly, a latch means normally holds the valve unitin operative connection with the tool and is arranged so that when afluid pressure greatly in excess of the normal well pressure is pumpeddown the pipe leading from a pump provided for the purpose at the top ofthe well, the latch means will release the valve unit for withdrawalfrom the tool by a wire line. The valve unit readily may be replaced onthe tool on a wire line and spudded into latched engagement with thetool by use of a set of jars.

Provision is also made at the top of the well for manually venting atwill, the annular chamber around the sleeve valve, to shut off the wellfiow at the tool, there being a manually operable vent valve in the pipeline for this purpose.

As shown in FIG. 1, a typical use of apparatus embodying the presentinvention is illustrated in connection with a flowing well situated in abody of water. This well includes a platform A supported on pilings B, aderrick C, a casing D extending from the platform into the submergedground E, and flow lines F connected in the usual manner with the casinghead G.

A shut-off tool 1 embodying the present invention is located in thecasing D and serves as a section of the tubing string S, only the lowerpart of this string being shown.

The tool I is anchored to the casing D at a safe distance, say, of theorder of or more feet, below the surface of the submerged ground.

After the tool I is anchored in the desired position, that part of thetubing string above the tool is uncoupled and removed from the well.Next, the upper end of the tool is closed by lowering a tubing plug 2and seating it in this upper end. The tool I is provided with ports 3which permit of free flow of the well below the plug 2 into the casingto the top of the well.

Trigger means, generally designated T, are mounted on the platform A forcontrolling the tool 1 in a manner to be hereinafter described. A pipeline 4 extending from the top of the well to the tool 1 operativelyconnects the trigger means with the tool 1.

A trigger valve unit 5 embodied in the trigger means T, is connectedwith the pipe line 4 and the casing head G and normally causes the fluidpressure in the well to be effective through the line 4 to the tool 1for control of.

the latter in a manner to be hereinafter described.

As it is the function of the tool to shut off the flow when an emergencyarises, for example, in the event of the platform and vulnerable partsof the well being struck a severe and damaging blow by a ship, barge, orother floating object or an object blown against the Well during highwinds and in stormy weather, the trigger means is arranged to respond tosuch accidentally applied forces and cause the tool to shut off the flowof the Well below the vulnerable parts of the well.

Accordingly, the tool 1 is provided with a spring-loaded shut-off valveunit 6 which is maintained in position with the ports 3 open but beingcounter-balanced by well pressure directed thereagainst from the pipeline 4 and the interior of the tool respectively. This valve unit,however, will move to a position closing the port 3 and shutting oifflow from the tool 1, incident to venting fluid from the tool throughthe line 4 to the atmosphere. This venting will take place responsive tooperation of the trigger valve unit 5 in the pipe line 4 as a result ofthe trigger means T being subjected to the aforementioned shocks orforces.

As shown in FIG. lb, the trigger means T includes a valve chamber 5arigidly secured to the casing head G and provided with an intake port 7,an outlet port 8 and a vent port 9. The port 7 is connected with thecasing head by means of a pipe 4a, whereas the pipe line 4 leading tothe tool 1 is connected with the outlet port 8.

Mounted to reciprocate in the chamber 5a is a valve stem on which aremounted piston-like valve members 11 and 12. The valve member 11 ismovable between positions opening and closing a passage 11a extendingbetween the ports 7 and 8, Whereas the valve member 12 is movablebetween a position opening and closing a passage 12a between the ports 8and 9.

The trigger means T also includes means which releasably holds the stem10 in a position such that valve member 11 opens the passage 11a betweenports 7 and 8 and closes the passage 12a leading to the vent port 9.When the stem 16 is released, the fluid pressure applied to the valvechamber from the well casing through the pipe 4a is effective againstthe valve member 12 so that the valve members 11 and 12 are caused tomove to positions closing the passage 11a and opening the passage 12a,thereby shutting off the flow from the well through the valve chamberand permitting the fluid pressure in the line 4 to vent to theatmosphere through the passage 12a and vent port 9.

Means for releasably holding the stem lit in position permitting fluidpressure from the well to be eifective in the pipe line 4, includes adisk 14 on the upper end of an upstanding post 15 rigidly secured at itslower end to an annular member 16. This annular member is positioned inan opening in the floor 17 of the platform A and has an annular flange18 bolted to the floor. The well casing extends through the annularmember 16 so that the latter is circumferentially spaced therefrom. Themember 16 is preferably made in arcuate sections to facilitate theassembly thereof around the casing.

With this arrangement of the member 16 and post 15, it is apparent thatlateral movement of the platform, member 16 and post 15 relative to thecasing will take place incident to the pilings or the platform beingsubjected to severe impacts such as described. Accordingly, the disk 14on the post 15 will be moved laterally with the platform and annularmember 16 to one side of the stem 10 which, as hereinbefore noted, willthen be moved by the fluid pressure from the well, into position to shutolf flow into the line 4 and open line 4 to the vent port 9 whereby theshut-off valve in the tool 1 will be closed.

As here shown, the stem 10 rests upon the center of the disk 14, as itis intended that the diameter or width of this disk be such that onlywhen a severe impact such as would rupture the casing or flow lines atthe top of the well, is sustained by the platform, will the disk 14 bemoved sufiiciently to release the stem and thereby cause the tool 1 toshut off flow into the well casing. Thus, it is apparent that by varyingthe diameter or width of the disk 14, the trigger means T may be set tocause the flow to be shut off at the tool 1 as best suited to theconditions at hand and so that anticipated minor shocks and jars beineffective to trip the trigger means.

The shut-off tool 1 as shown in FIGS. 1-6 includes a tubular body 20adapted to be coupled in the tubing string as a section thereof. Atubular plug seat 21 connects the upper end of the body 20 with theportion of the tubing string above the tool in such manner that afterthe tool is set in the desired position in the well casing, the portionof the tubing string above the plug seat may be uncoupled from thelatter and removed from the well. After this upper portion of the tubingstring is removed, the tubing plug 2 is lowered and set in the seat 21to shut off flow from the seat into the well casing.

A sectional tubular member 22 surrounds the body 20 in circumferentiallyspaced relation thereto to provide an annular passage 23 therebetween. Acoupling member 24' having ports 24 therein, provides for connection ofthe body 20 with that portion of the tubing string extending below thebody, as well as for connection of the outer tubular member 22 with thebody 1 and tubing string. The ports 24 provide for the flow of the wellfluids from the casing below the tool into the annular passage 23,thence through the ports 3 into the casing above the tool.

The upper part of the outer tubular member 22 comprising the threadedlyconnected tubular sections 26, 27 and 28 forms a part of the retrievableshut-off valve unit 6, wherein the valve element comprises a sleeve 29movable axially between positions opening and closing the ports 3, whichlatter are formed in the tubular section 27. The remainder of thesectional tubular member 22 includes tubular sections 30, 31, 32, and 33thrcadedly connected one to the other and located in the order named,below the sleeve valve 29 and the tubular section 28. In thisconnection, it should be noted that the lower end of section 28 istelescopically and removably fitted in a counterbore 3% in the section30 so that the valve unit 6 may be removed as will be hereinafterdescribed.

The tubular sections 27 and 28 and the sleeve valve 29 are constructedand arranged to define an annular pressure chamber 34 between theexterior of valve 29 and the interior of the sections 27 and 28. Thus,the upper portion of the sleeve valve 29 is slidably engaged with aninternal enlargement 35 of the section 27, which latter defines ashoulder 36 forming the upper end of the chamber 34, there being asealing ring 37 on this enlargement for sealing against the sleevevalve. In this connection, it should be noted that the sleeve valve 29is circumferentially spaced from the body 20 so that the resultantannular space therebetween becomes a part of the fluid passage 23between the ports 24 and the ports 3 at the respective ends of passage23. The upper end of this passage is closed by on internal enlargement38 in the uppermost tubular section 26, there being a sealing ring 39 inthis enlargement to seal against the body 2i).

The lower end of the sleeve valve 29 is provided with an external flange4t) slidably engaged with the internal surface of the tubular section 28to define the lower end of the pressure chamber 34, there being asealing ring 41 in the flange 40 for sealing against the section 28.

The pipe line 4 is connected with a port 42 formed in the tubularsection 30 of the outer tubular member 22, this port being incommunication with a passage 43 formed in the tubular section 28. Thepassage 43 opens through a port 44 into the pressure chamber 34, therebyproviding for the introduction of well pressure through the line 4, port42, passage 43, and port 4 into the chamber 34, whereby the fluidpressure against the exterior of the sleeve valve 29 may be equalled tothe pressure within the passage 23, to hydraulically balance the sleevevalve when it is in the open position. Sealing rings 45 and 46 carriedby the section 28 are arranged to seal against the section 30 above andbelow the point of communication of the port 42 with the passage 43.

To assure that the sleeve valve 29 be maintained in open positionuncovering the ports 3, a spring 47 is mounted in the chamber 34- insurrounding relation to the sleeve valve with its ends abutting theshoulder 36 and flange 46 respectively.

Latch means are provided for releasably holding the section 28 incoupled relation to the section 30. This latch means includes a seriesof spring latch elements 48 integral with a tubular member 49threadingly coupled to the section 30. These latch elements releasablyengage a shoulder 50 internally of the section 28 below the valve 29.The outer ends of the spring latch elements 48 have cam surfaces 51which are engaged by an annular cam surface 52 on the lower end of thesleeve valve 29 when the latter is in a poistion uncovering the ports 3as shown in FIG. 3. When in this position, the valve 29 is above ashoulder 53 on the section 28, this shoulder acting as a stop when thevalve is moved downwardly for forcing the spring latch elements 48 outof latching engagement with the latch shoulder 59.

When it is desired to release the valve unit 6, which includes the uppertubular sections 26, 27, and 28 and the sleeve valve 29, pump P such asshown in FIG. 1 in dot dash lines, is connected with the line 4 andoperated to force fluid under pressure greater than the well pressure,into the chamber 34. This greater pressure will cause the valve 29 tomove downwardly against the stop shoulder 53 and in so moving the camsurfaces 51 and 52 cooperate to force the latch elements into releasingposition shown in FIG. 5. The valve unit 6 may now be removed with awire line, for inspection or parts replacement, and tl ereafter replacedby the aid of a wire line and jars to snap it into latched engagementwith the latch members .9.

Packing means are provided on the tool for sealing against the casingand, as shown in FIG. 2a, includes an expansible sleeve packer 55confined on the section 32 between a shoulder 56 on the section 32 and afloating slip expander 57 surrounding the sections 32 and 33. Thispacker is normally relaxed and free from contact with the casing wherebythe tool readily may be lowered into the well casing on the tubingstring.

Slips 66 are engaged with the expander 57 so as to be moved laterallyinto anchoring engagement with the casing responsive to relativemovement between the slips and the expander. These slips are connectedby links 61 with a floating sleeve 62 mounted on the tubular section 33.The sleeve 62 mounts a plurality of spring loaded shoes 64 which areemployed instead of conventional drag springs, to frictionally engagethe casing whereby relative movement between the slip and the slipexpander may be effected upon lowering of tubing string.

Means are provided for releasably locking the slips 6%) in retractedposition as well as for holding the sleeve packer 55 in relaxed positionfree from contact with the casing. In other words, this locking meansreleasably holds the sleeve 62 and tubular members 21: and 22 againstrelative axial movement, but permits of relative rotation between thesleeve and members 20 and 22 to release sleeve 62 and members 20 and 22for relative axial movement. As here shown, the locking means includes aplurality of locking segments 65 confined between op posed shoulders d6and 67 on threadedly connected tubular members 68 and 169. The tubularmember 68 is threadedly coupled to the lower end of the sleeve 62. Thesegments 65 have screw threads 69 on the inner surfaces thereof and areheld in annular formation around the tubular section 33 by means of apair of coiled springs 70 which surround the segments and are seated ingrooves 71 on the outer surfaces of the segments. With this arrangementthe segments 65 are yieldable radially but are held against rotativemovement by lugs 72 welded to the member 68 and extending between thesegments as indicated in FIG. 2b.

The other element 73 of the locking means is in the form of a screwthreaded enlargement on the exterior of the tubular section 22. Thescrew threads on the segments 65 cooperate to threadedly engage thescrew threaded element 73 for locking the sleeve 62 and tubular members29 and 22 against relative axial movement. These coacting screw threadsare of such formation that upon appropriate rotative movement of members20 and 22 relative to the sleeve 62, the screw threaded element 73 willbe unscrewed from the segments 65 and lowered relative thereto, theshoes 64 then restraining rotation of the sleeve 62. When it is desiredto relock the element 73 with the segments 65, it is only necessary tolift the members 20 and 22 so that the element 73 will snap into lockedengagement with the segments 65. The screw threads on the segments 65and locking element 73 are shaped so as to cam past one another as theelement 73 is moved upwardly against the segments 65, the latteryielding radially outwardly against the action of the springs 70 duringthis camming action and then urging the segments into threaded andlocked engagement with the enlargement 73.

Additional anchoring means is provided on the tool to hold the latter inplace, in the event the shut-off valve unit, that is, the sleeve valve29, is moved into position to close the ports 3 and thus shut oir theflow at the tool 1. This additional locking means is actuated by thefluid pressure in the well when the latter is shut oif at the tool andincludes a plurality of rows of axially spaced cylinders 75 formed inthe tubular section 31. Pistonlike slips '76 are mounted in thecylinders so that the toothed outer ends of the slips are disposed togrip the casing. These fluid pressure actuated slips are normallysubstantially hydraulically balanced and ineffective for anchoring thetool until the well flow is shut off at the tool as hereinbefore noted.When the flow is shut off at the tool the pressure drop across the outerends of the slips 76 permits the pressure against the inner ends of theslips to urge the slips into anchoring engagement with the casing.

As shown in FIG. 2, a sleeve is mounted within the tubular section 31 incircumferentially spaced relation to body 20 as well as to the innerends of the cylinders 75, to define an annular pressure chamber 78. Thispressure chamber is in constant communication with the passage 23through a port 79 at the lower end of the sleeve 77. The sleeve 77 isconfined between shoulders 80 and 81 on the tubular sections 30 and 31respectively.

Provision is made for manually shutting off the well at the tool 1.Accordingly, the pipe line 4 at the top of the well is provided with avent pipe 83 controlled by a valve 84. When the valve 84 is opened, thefiuid pressure in the chamber 34 of the valve unit 6 is vented to theatmosphere; whereupon the fiuid pressure interiorly of the sleeve valve29 will be effective to move the sleeve valve upwardly to close theports 3 thereby shutting oil the flow of the well at tool ll.

Other controls of the flow in the pipe lines 4a and 4 at the top of thewell include a manually operable valve 85 in the line 4 a between thecasing head and trigger valve unit 5, a similar valve 86 between thetrigger valve unit 5 and the line 4 leading to the shut-off valve unit 6in the tool 1, and a manually operable valve 87 in a pipe 38, whichlatter provides for connection with the pump P with the line 4. Thisconnection of the pump P is made when it is desired to retrieve theshut-01f valve unit 6 in the manner hereinbefore described. Thisarrangement of valves 85, 86, and 87 provides for a complete manualcontrol of the flow through the lines 4:! and 4.

It should be noted that the tubing plug 2 is provided with a neck 2awhereby standard wire line equipment,

sisasoo 9 not shown, may be employed to remove and replace the plug.

As shown in FIGS. 3 and 13, lugs 89 are provided on the lower end of thetelescopically mounted tubular section 28 for contacting similar lugs 90on the tubular section 30 in which the section 28 is telescoped.

Operation A tubing string, only the lower part S of which is here shown,is employed to position the tool 1 with the pipe line 4 in the wellcasing at the desired location below the surface of the submergedground.

After the tool is disposed at the desired depth, the tubing string,together with the tool members 20 and 22, are appropriately rotated tounscrew the locking element 73 from the locking segments 65 on thefloating sleeve 62. This sleeve is restrained against rotation by thefriction shoes or engaged with the casing.

When the locking element 73 is released from the segments 65 the toolmembers 20 and 21 may be moved axially relative to the sleeve 62, whichlatter is then restrained against axial movement by the shoes 64 engagedwith the Well casing.

Upon now moving the tubing string downwardly, the tool members 20 and 22move correspondingly and through the sleeve packer 55 exert a forceurging the expander '7 downwardly relative to the slips 69, therebymoving the slips into engagement with the casing and anchoring the toolin the well. This anchoring action causes the packer 55 to be expandedinto sealing engagement with the casing.

Next, the portion of the tubing string leading upwardly from the plugseat 21 at the top of the tool is uncoupled and removed irom the well.The seat 21, in effect, is now the upper end of the tubing string in thewell, and is plugged by lowering the plug 2 into the seat on a wireline.

The pipe line 4, trigger valve unit 5 and related trigger elements arenow set up at the top of the well, with the valve unit 5 and line 4 incommunication with the casing head. The valve unit 5 and line 4 providefor the introduction of the fluid pressure in the well into the chamber34 in the shut-ofl valve unit 6 in the tool, thereby, as hereinbeforedescribed, hydraulically balancing the sleeve valve 29 so that thespring 47 will be eiiective to assure holding the valve open wherebynormal flow of the well may take place.

When the tool is anchored in the casing :and the valve 29 balanced andheld open, the tool is in readiness to protect the well. At this timethe hydraulically actuated slips 76 are ineflective to anchor the toolas the fluid pressure of the well is effective against the outer ends ofthe slips as well as against the inner ends thereof.

In the apparatus shown in FIGS. 1-6, the lower part of the well isarranged so that the well fluid will enter the tool from the portion ofthe casing next below the tool, rather than from that portion of thetubing string S adjacent the tool. It is believed to be unnecessary toillustrate the arrangement of the well which provides for the flow ofthe well products through the tool, as it is plain that the upwardlyflowing products, in the casing below the tool, will enter the toolthrough the ports 24 and flow through the annular passage 23 and ports 3into the casing above the tool, thence to the top of the well.

It will now be apparent that with the tool 1 installed in a well asshown in FIGS. 1 and 1a, should the platform A or pilings B, sustaincollision forces or similar impacts of a severity which would damage thewell and cause loss of the well products, the platform will moverelative to the well casing and cause the disk 14 to move clear of thevalve stem 10 of the trigger valve unit 5. When this action takes placethe fluid pressure of the well elfective in the valve unit 5 will causethe valve member 12 to move to a position (see FIG. 1b) communicatingthe pipe line 4 with the vent port 9, at the same time the valve member11 shuts ofl the flow from the well to the pipe line 4, therebyrelieving the pressure in the chamber 34 of the valve unit 6. Incidentto this release of the fluid pressure from the chamber 34, the fluidpressure in the passage 23 is eiiective against the interior surface ofthe sleeve valve 29 and causes this valve to move upwardly against theaction of the spring 47 into a position closing the ports 3 and shuttingoff the flow at the tool.

It will be apparent that a shut-off tool such as hereinbefore described,when installed in a well and arranged to be operated responsive to thetrigger means T as here shown, will prevent the loss of valuableproducts of the well, in the event the vulnerable portion of the well atthe surface is subjected to damaging shocks and imp-acts.

As shown in FIGS. 7-l1, a modified form of "shut-off tool embodying thepresent invention, ditiers from the tool shown in FIGS. 1-6 in that itdoes not include a sectional tubular member jacketing the tool body,such as the member 22 forming the outer section of the tool shown inFIGS. 16. Instead, the modified tool includes a sectional tubular body160 which is adapted to be connected in a tubing string in the samemanner as the body 20 in the tool shown in FIGS. 1-6, and provided atits upper end with a plug seat 101 for reception of a plug to shut Offflow of well fluid through the plug seat.

This tool is installed in the same manner as the tool shown in FIG. 1,subject to control by the same trigger means as shown in FIGS. l-lbincluding a pipe line 1132 leading to a pressure chamber 103 surroundinga sleeve valve 164. This sleeve valve corresponds to sleeve valve 29shown in FIG. 2, being axially movable within the body 166 betweenpositions for opening and closing ports 195 formed in the upper end ofthe body ltit). The ports 105 when uncovered by the valve 1114 providefor normal flow of the well fluids from the tubing string V below thetool, through the body ltltl and into the casing 106, thence to the topof the well.

A spring 197 surrounds the sleeve valve 104 with its ends abuttingshoulders '108 and 1119 on the body 1% and valve respectively, fornormahy holding the valve in open position.

The pipe line 102 is connected with a port 1 10 in a section 111 of thebody 1%, this port being in communication with a passage 112 formed inthe section 113 of the body 111% leading into the chamber 163 in thesame manner as shown in FIG. 3. When the fluid pressure from the casinghead is conducted through pipe line 102 into the chamber 163, theexterior of the valve 134 is exposed to substantially the same pressureas the interior of the valve, thereby providing -a hydraulic balancewhereby the spring 1117 is eifective to hold the valve in open positionas shown in FIGS. 7 and 8.

When the fluid pressure is relieved from the chamber 103 through theline 192 and trigger means in the same manner as described in connectionwith the apparatus shown in FIGS. 1-6, the fluid pressure in the body 1%becomes eflective against the valve 194 and moves the valve against theaction of the spring 1&7 into position to close the ports 195.

The plug seat 1111 and the threadedly connected tubular sections 115 and113 of the body 1011, together with the sleeve valve 164 constitute aretrievable unit as the lower section 113 is telescopically andremovably mounted in the section 111 of the body 109.

Latch means identical with the latch means shown in FIGS. 2 and 3 areprovided for releasably holding the tubular section 113 in telescopicengagement with the section 111. This latch means comprises spring latchfingers 117 fixedly connected with the section 7111 and arranged toengage an internal shoulder 1-18 on the section 113. The lower end ofthe valve M14 is provided with a cam surface 120 normally in contactwith the cam surfaces 121 on the free ends of the latch fingers 117.

When it is desired to release the valve unit, fluid pressure in execssof the well pressure is pumped down the pipe line 192 from the top ofthe well in the same manner as described in connection with the firstdescribed form of this invention.

The fluid pressure thus developed in the chamber 103 will be effectiveto force the valve 104 downwardly whereby the cam surfaces will coact toforce the fingers 117 inwardly free of the shoulder 118, therebyreleasing the valve unit, which may be removed and replaced on a wireline.

This modified tool is provided with expansible packing rings 123, afloating slip expander 124, slips 125, and links 126 connecting theslips with a floating sleeve 127, all mounted on the body 100. Thesleeve 127 carries spring-loaded shoes 128 for frictionally engaging thecasing.

The expansible ring packers 123 are confined between a shoulder 129 orthe body 160 and the upper end of the expander 124 whereby on moving thebody downwardly relative to the sleeve 127, the ring packers will forcethe expander downwardly to set the slips. Continued movement of the body101 downwardly will cause the packers to expand into sealing engagementwith the casing.

Locking means 131 substantially identical with the locking means shownin FIGS. 2a and 2b are provided for holding the sleeve 127 and body 120against relative axial movement. This locking means includesspringloaded screw threaded segments 132 on the sleeve 127 and a screwthreaded locking element 133 on the body 100. Lugs 133' on the sleeveextend between the segments 132 to hold them against rotation. Thelocking segments and the element 133 are operable in the same manner asdescribed in connection with the tool shown in FIGS. 16.

A hydraulically actuated anchoring unit 134 is provided on body 100between the packer rings 123 and the body section 111. This unitincludes cylinders 135 formed in the body 1% and piston-like slips 136,identical with the cylinder slips shown in FIG. 2. A tubular member 137is mounted in the body 100 in spaced relation to the inner ends of thecylinder 135 to define an annular pressure chamber 139. A port 140 inthis tubular member 137 provides for the introduction of the fluidpressure from the body 101 into the chamber 139 for forcing the slips136 into anchoring engagement with the casing. However, when the valve194 is open, the fluid pressure exteriorly of the body 100 against theouter ends of the slips is substantially equal to the fluid pressure inthe chamber 139 whereby the slips are substantially hydraulicallybalanced. When the pressure in the chamber 139 increases incident to theclosing of the sleeve valve 104, the slips 135 will be forced by theincreased pressure into anchoring engagement with the casing. With thisarrangement the anchoring action increases according to the increasedwell pressure, thereby assuring that the tool will remain properlyanchored in the well while the valve 164 shuts ofl? flow from the toolto the top of the well.

Provision is made in this modified tool to prevent rotation of the valveunit including the tubular sections 115, 113 and the sleeve valve 154relative to the remainder of the body 190, in the same manner as in thetool shown in FIGS. l6. Accordingly, lugs 143 and 144 on sections 113and 111 respectively, are adapted to engage one another to prevent suchrotation, these lugs being the same construction and arrangement as thelugs 85* and 30 shown in FIG. 13. In this modified construction it maybe desirable to make up a tubing string in the plug seat 161 while thetool is in the well, and the lugs 143 and 144 will prevent relativerotation of the tubular member 113 within the body member 111.

FIG. 12 illustrates another modified form of tool 146 embodying thisinvention, wherein the same elements as in the tool shown in FlGS. 1-6are provided except that the packing means including an expansiblesleeve packer 147, is actuated in a different manner than in the toolshown in FIGS. 16. In the tool 146, the casing 148 is provided with aconical restriction 149 in which a floating conical member 150 isengageable. The sleeve packer 147 is confined between the upper end ofthe conical member and a shoulder 151 on the sectional outer tubularmember 152 of the tool. The tubular body 153 of the tool is connected inthe tubing string 154 in the same manner as the body 20 of the toolshown in FIGS. 1-6. The body 153 and the outer sectional tubular member152 are connected with one another and the tubing string by means of acoupling member 155 in the same manner as shown in FIG. 2a, there beingports 156 in the member 155 corresponding to the ports 24 shown in FIG.2a.

The packer 147 is expanded into sealing engagement with the casing 148by lowering the tubing string and tubular members 152 and 153 of thetool, thereby compressing the packing between the member 150 and theshoulder 151. In all other respects the tool 146 is operated in the samemanner as the tool shown in FIGS. 16.

There is illustrated in the drawings and described above a subsurfacevalve assembly 6 in which the spring 47 acts on the valve sleeve in adirection such as to supplement the force derived from the action ofpressure in the control tube 4 on the surface of flange 40 in thechamber 34 of the valve assembly. It will be understood, however, bythose of ordinary skill in the art that the position of valve sleeve 29in the body 27 will be determined by the net force acting in onedirection or the other to move the valve sleeve to an open position orto hold the valve sleeve in such position or to move the valve sleeve toa closed position. Obviously, therefore, the spring is not essential toopening or holding open of the valve 6, since fluid pressure alone inchamber 34, supplied through control tube 4, and acting on the valvesleeve flange 4%) plus the weight of the valve and friction issuflicient to overcome the effect of well pressure acting oppositely onthe flange 4t and thereby maintain the valve in open position.

Within the clear purview of the various modes of controlling theposition of the valve sleeve 29, venting of the control tube toatmosphere may be accomplished by means of the trigger valve 5hereinabove described, by the manual vent valve 84 or by other desiredvalve means, as well as upon rupture of the well head equipment, as isobvious, in any of which cases pressure in the well may cause closure ofthe valve.

Whether or not the spring 47 be present in the valve assembly 6, thevalve will be opened and/ or held open when the force acting downwardlyon valve sleeve 29 overcomes the force acting upwardly thereon. When itis desired to open the valve assembly 6, as is apparent from theforegoing, it is only necessary to supply sufficient pressure throughcontrol tube 4 to the valve chamber 34 to overcome the upward forcesthereon, thereby moving the valve sleeve downward to the position shownin FIG. 3, for example, wherein the ports 3 are open. The flow ofproduction fluid to the top of the well through ports 3 will provide, inaccordance with one of the features of the invention, fluid pressurewhereby the valve sleeve 29 may be held open. One source of fluidpressure for opening the valve as aforesaid has been described above asbeing useful also to move the valve sleeve 29 downwardly to unlatch thefingers 43 from the valve body. Obviously, the pressure source or pump Pis also useful to move the valve to an open position and the pump Ptherefore is preferably a source of variable pressure, since asubstantially greater pressure would be required to unlatch the fingers48 than would be required merely to open the valve 6.

The various structural details as herein shown and described are by wayof illustration of an embodiment of the invention, but changes andalterations may be resorted 13 to and equivalent sub-assemblies andcomponents may be employed without departing from the scope of thefollowing claims.

We claim:

1. Apparatus for protecting a flowing well against the loss of fluidproducts of the well from a conduit at the top of the well, including:means at the top of the well adapted to be moved by forces which ifsustained by the conduit at the top of the well would cause such loss;valve means located in the well below said flow structure, said valvemeans including a body open to Well fluids therebelow and having apassage leading to the well above the valve means from said body; avalve element in said body shiftable to a position closing said passageto close the valve means and to a position spaced from said passage toopen the valve means; said element having a first fluid pressureresponsive surface for hydraulically holding said valve means open and asecond fluid pressure responsive surface for hydraulically closing saidvalve means; and means including a conduit connected with said firstnamed means, said flow conduit and said valve means for conducting fluidunder pressure from said flow conduit to said first fluid pressureresponsive surface to permit flow of the Well.

2. A well tool including: a tubular body adapted to be anchored in awell; packing means on the body operable for sealing against the Wall ofthe well; anchoring means on the body operable to anchor the tool in thewell; valve means in the body for controlling the well flow through thebody; means associated with said valve means operable for maintainingsaid valve means open when the valve means is hydraulically balanced inthe well; said valve means being constructed and arranged to be closedby the fluid pressure in the well when hydraulically unbalanced in thewell; and hydraulically operable anchoring means carried by said bodyoperable to anchor the tool in the well responsive to the fluid pressurein the well upon the closing of said valve means.

3. A well tool including: a tubular body adapted to be anchored in awell; packing means on the body operable for sealing against the wall ofthe well; anchoring means on the body operable to anchor the tool in thewell; valve means in the body for controlling the well flow through thebody; and means associated with said valve means operable formaintaining said valve means open when the valve means is hydraulicallybalanced in the well; said valve means being constructed and arranged tobe closed by the fluid pressure in the well when hydraulicallyunbalanced in the well; said valve means including means adapted to becontrolled from the top of the well for effecting said hydraulic balanceas well as said hydraulic unbalance; and hydraulically operableanchoring means arranged to be substantially hydraulically balanced andineifective as an anchor when said valve means is hydraulicallybalanced; said hydraulically operable anchoring means being operable toanchor the body in the well responsive to the fluid pressure in the wellwhen said valve means is closed.

4. A well tool including: a tubular body adapted to be anchored in awell; packing means on the body operable for sealing against the Wall ofthe Well; anchoring means on the body operable to anchor the tool in thewell; said body having a port above said packing means for conductingfluid from said body into the well above said body; a sleeve valveshiftably disposed in said body; means for shifting said sleeve valve inopposite directions to open and close said port including internal andexternal surfaces on said sleeve valve responsive to fluid pressure;said internal surface being exposed to well fluid pressure; meansincluding a conduit leading from the top of the well for conducting wellfluid pressure to said ex ternal valve sleeve surface; and means at thetop of the well and connected with said conduit for controlling theapplication of well pressure through said conduit to said externalsleeve valve surface to cause said port to be maintained open.

5. A well tool including: a tubular body adapted to be anchored in awell; packing means on the body operable for sealing against the wall ofthe well; anchoring means on the body operable to anchor the tool in thewell; said body having a port above said packing means for conductingfluid from said body into the Well above said body; a sleeve valveassociated with said body for opening and closing said port; said valvehaving its internal and external surfaces exposed for applicationthereto of fluid pressure; a conduit connectable to a source of wellfluid pressure at the top of the well and connected to said body abovesaid packing means and below said port for applying fluid pressureexternally of said valve; and means operable at the top of the well andconnected with said conduit for controlling the application of fluidpressure externally of said valve to cause said valve to be held openand closed responsive to fluid pressure derived from the well.

6. A well tool adapted to be anchored in a well, including: a tubularbody for conducting fluid therethrough; a packer on said body forsealing against the wall of the well; means on the body for anchoringthe body in the well; said body having a port above said packer forconducting fluid into the well above said body; a sleeve valve in thebody movable axially to close and open said port; means providing apressure chamber on the body surrounding the exterior surface of saidvalve; the interior surface of said valve being positioned for exposureto fluid pressure in said body; said valve being hydraulically balancedwhen fluid pressure is applied internally and externally thereof: springmeans urging said valve to a position opening said port when said valveis hydraulically balanced; a conduit connected to said body and leadingto said pressure chamber and to the top of the well; and means connectedto said conduit at the top of the well for introducing fluid pressureinto said conduit and consequently said chamber and venting fluidpressure from said conduit and consequently said chamber tohydraulically balance and unbalance said valve.

7. A well tool adapted to be anchored in a well, including: a tubularbody for conducting fluid therethrough; a packer on said body forsealing against the wall of the well; means on the body for anchoringthe body in the well; said body having a port above said packer forconducting fluid into the well above said body; a sleeve valve in thebody movable axially to close and open said port; means providing apressure chamber on the body surrounding the exterior surface of saidvalve; the interior surface of said valve being positioned for exposureto fluid pressure in said body; spring means urging said valve to aposition opening said port; means on said body providing a passageadapted to be controlled from the top of the well for introducing fluidpressure into said chamber and venting fluid pressure from said chamber;and hydraulically actuated anchoring means on said body above saidpacking means operable to move into anchoring engagement with the wallof the well responsive to fluid pressure in the well above the packerwhen said valve closes said port.

8. A well tool adapted to be anchored in a Well, including: a tubularbody composed of a pair of concentric circumferentially spaced tubularmembers defining an annular flow passage; said body having upper andlower ports which open into said passage; a sleeve valve axially movablebetween said tubular members for opening and closing said upper port;means providing a pressure chamber between said tubular members belowsaid upper port and in surrounding relation to said valve; the interiorsurface of said valve being exposed to fluid pressure in the well;packing means on said body below said chamber for sealing against thewell wall; means on said body for anchoring said body in a well; saidvalve being hydraulically balanced when fluid pressure is applied to theexterior and interior thereof; spring means surrounding said valve insaid chamber urging said valve to open said upper port while said valveis hydraulically balanced; and passage means in said body leading intosaid chamber from the exterior of said body for introducing fluid underpressure from the Well above said body into said chamber as well as forventing fluid from said chamber.

9. A well tool adapted to be anchored in a well, including: a tubularbody composed of a pair of concentric circumferentially spaced tubularmembers defining an annular flow passage; said body having upper andlower ports adjacent its ends opening into said passage; a sleeve valveaxially movable between said tubular members for opening and closingsaid upper port; the interior of said valve being exposed in said flowpassage; means providing a pressure chamber within the outer tubularmember of said body below said upper port and in surrounding relation tosaid valve; said chamber providing for hydraulically balancing saidvalve when equal fluid pressures are provided in said flow passage andsaid chamber; a packing means on said outer tubular member below saidchamber for sealing against the well wall; means on said outer tubularmember for anchoring said body in a well; spring means surrounding saidvalve in said chamber urging said valve to open said upper port; andpassage means in said outer tubular member for introducing fluid underpressure from above said body into said chamber as well as for ventingfluid from said chamber.

10. A well tool adapted to be anchored in a well, including: a tubularbody composed of a pair of concentric circumferentially spaced tubularmembers defining an annular flow passage; said body having upper andlower ports adjacent its ends opening into said passage; a sleeve valveaxially movable between said tubular members for opening and closingsaid upper ports; the interior of said valve being exposed in said flowpassage; means providing a pressure chamber within the outer tubularmember of said body below said upper port and in surrounding relation tosaid valve; said chamber providing for hydraulically balancing saidvalve when equal fluid pressures are provided in said flow passage andsaid chamber; a packing means on said outer tubular member below saidchamber for sealing against the well Wall; means on said outer tubularmember for anchoring said body in a well; spring means surrounding saidvalve in said chamber urging said valve to open said upper port; andpassage means in said outer tubular member for introducing fluid underpressure from above said body into said chamber as well as for ventingfluid from said chamber; and means for anchoring said body in the wellmounted on said outer tubular member for operation by fluid pressure insaid flow passage incident to the closing of said upper port.

11. A well tool adapted to be embodied in a well, including: a tubularbody having a port for conducting fluid into the well above the body;packing means on said body below said port for sealing against the wallof the well; means on said body for anchoring the body in the well; asleeve valve axially movable within said body for opening and closingsaid port; the interior surface of said valve being exposed to pressureof well fluid; means on said body providing a pressure chambersurrounding said sleeve and providing for hydraulically balancing saidvalve when fluid pressure in said chamber against the exterior of saidvalve is equalled to fluid pressure in said body against the interior ofsaid valve; spring means in said chamber surrounding said valve urgingsaid valve to position opening said port when said valve ishydraulically balanced; and means on said body providing a passage forintroducing well pressure from the exterior of said body into saidchamber as well as for venting fluid pressure from said chamber.

12. A well tool adapted to be anchored in a well, including: a tubularbody; an expansible packer on said body; means on said body foranchoring the body in the well; means on said body operable forexpanding said packer into sealing engagement with the wall of the wellresponsive to actuation of said anchoring means; said body having a portabove said packer for conducting fluid from below the body into the wellabove the body; a sleeve valve associated with said body for move mentto open and close said port; said valve means being positioned forexposure to the well pressure in said body; means providing a pressurechamber on said body surrounding said valve; means on said body abovesaid packer providing a passage for conducting the fluid in the wellabove said body into said chamber as Well as for venting fluid from saidchamber; spring means in said chamber urging said valve into a positionopening said port and yielding to permit said valve to close said portresponsive to the fluid pressure in said body eflective against saidvalve, when the pressure in the chamber is vented therefrom; andhydraulically operated anchoring means operable to anchor the body inthe well responsive to the closing of said valve.

13. A well tool including: a tubular body adapted to be positioned in awell on a tubing string; a tubular plug-receiving seat for detachablyconnecting the upper end of the body with the tubing string; means onthe body for anchoring the body in the well; said seat adapted to beclosed by a plug after detaching from the seat and removing from thewell the portion of the tubing string extending from the seat to the topof the well; said body having a port below said plug seat for conductingfluid from the tool into the well above the body; packing means on thebody below said port for sealing against the wall of the well; valvemeans on the body for opening and closing said port; and means embodiedin the tool for causing said valve to open and close said port; saidlast named means being constructed and arranged to be controlled fromthe top of the well.

14. A well tool including: a tubular body; means on the body foranchoring the body in the well; a retrievable valve unit on said body;said valve unit including tubular means surrounding said body anddefining a pressure chamber having a port for conducting fluid underpressure into and from said chamber; a sleeve valve in said chambersurrounding said body; said tubular means having a port above saidchamber for conducting well fluid from the body into the well above thebody; said sleeve valve being movable to open and close said secondnamed port; latch means on said body for releasably holding said tubularmeans in operative engagement with said body; said latch means includingspring latch elements on said body releasably engaged with said tubularmeans and disposed to be engaged by said sleeve valve and moved therebyto release said tubular means upon movement of said valve in onedirection responsive to a fluid pressure in said chamber.

15. A well tool including: a tubular body; means on the body foranchoring the body in the well; a retrievable valve unit on said body;said valve unit including tubular means surrounding said body anddefining a pressure chamber having a port for conducting fluid underpressure into and from said chamber; a sleeve valve in said chambersurrounding said body; said tubular means having a port above saidchamber for conducting well fluid from the body into the well above thebody; said sleeve valve being movable to open and close said secondnamed port; latch means on said body for releasably holding said tubularmeans in operative engagement with said body; said latch means includingspring latch elements on said body releasably engaged with said tubularmeans and disposed to be engaged by said sleeve valve and moved therebyto release said tubular means upon movement of said valve in onedirection responsive to a fluid pressure in said chamber exceeding thefluid pressure of the well.

16. A well tool including: a tubular body; means on the body foranchoring the body in the well; a retrievable valve unit on said body;said valve unit including tubular means surrounding said body anddefining a pressure chamber having a port for conducting fluid underpressure into and from said chamber; a sleeve valve in said chambersurrounding said body; said tubular means having a port above saidchamber for conducting well fluid from the body into the well above thebody; said sleeve valve being movable to open and close said secondnamed port; and means for releasably holding said valve unit inoperative connection with said body including, spring latch members onsaid body engageable with said tubular means; and cooperable camsurfaces on said valve and said latch members operable to disengage saidlatch member from said tubular means upon movement of said valve meansresponsive to a fluid pressure in said chamber exceeding the wellpressure.

17. Apparatus for protecting a flowing well having casing thereinagainst the loss of the fluid products therefrom in the event thestructure of the well above the ground is subjected to a damaging force,including; means operatively connected with said structure arranged tobe subjected to such a force and moved before the casing of the well issubjected to said force; and means located in the well and connectedwith said first named means for shutting oif the flow of the wellresponsive to said first named means being moved when subjected to saidforce; said means for shutting off well flow including a fluid pressureoperated valve, and means for subjecting said valve to pressure from thewell at the ground surface for maintaining said valve open.

18. Apparatus for protecting a flowing well against the loss of thefluid products therefrom in the event the structure of the well abovethe ground is subjected to a damaging force, including: a tubular bodypositioned in the well casing; said body having a port for conductingfluid from below the body into the well above the body; a sleeve valveaxially movable in said body to open and close said port; meansproviding in the body a pressure chamber surrounding said valve; saidvalve being positioned for exposure of its interior and exteriorsurfaces to the pressure of fluid in said body and said chamberrespectively, whereby the valve may be substantially hydraulicallybalanced; spring means urging said valve to a position opening saidport; a fluid line connecting the casing at the top of the well withsaid chamber for conducting fluid under pressure from the casing to saidchamber, as well as for venting fluid under pressure fromsaid chamber;trigger valve mechanism at the top of the well for controlling the flowthrough said line; said trigger valve mechanism including a vent portand valve means; said valve means being biased by fluid pressure fromthe well to occupy a position shutting off flow of well fluid throughsaid line to said pressure chamber and permitting the venting of fluidfrom said chamber and said line through said vent port; and triggermeans releasably holding said valve means in a position closing saidvent port and permitting flow of well fluid through said line into saidpressure chamber; said trigger means including a member operativelyconnected with said structure at the top of the well for movementrelative to the well casing and said flow line, upon being subjected tosaid force; and means operatively connecting said member with said valvemeans for releasing said valve means responsive to said member beingmoved a predetermined extent relative to said casing when subjected tosaid force.

19. Apparatus for protecting a flowing well against the loss of thefluid products therefrom in the event the structure of the well abovethe ground is subjected to a damaging force, including: a tubular bodypositioned in the well casing; said body having a port for conductingfluid from below the body into the well above the body; a sleeve valveaxially movable in said body to open and close said port; meansproviding in the body a pressure chamber surrounding said valve; saidvalve being positioned for exposure of its interior and exteriorsurfaces to the pressure of fluid in said body and said chamberrespectively,

whereby the valve may be substantially hydraulically balanced; springmeans urging said valve to a position opening said port; a fluid lineconnecting the casing at the top of the well with said chamber forconducting fluid under pressure from the casing to said chamber, as wellas for venting fluid under pressure from said chamber; trigger valvemechanism at the top of the well for controlling the flow through saidline; said trigger valve mechanism including a vent port and valvemeans; said valve means being biased by fluid pressure from the well tooccupy a position shutting off flow of well fluid through said line tosaid pressure chamber and permitting the venting of fluid from saidchamber and said line through said vent port; and trigger meansreleasably holding said valve means in a position closing said vent portand permitting flow of well fluid through said line into said pressurechamber; said trigger means including a member operatively connectedwith said structure at the top of the well for movement relative to thewell casing and said flow line, upon being subjected to said force; andmeans operatively connecting said member with said valve means forreleasing said valve means responsive to said member being moved apredetermined extent relative to said casing when subjected to saidforce; and means operatively connected with said flow line optionallyoperable for venting fluid pressure from said chamber.

20. Apparatus for protecting a flowing well against the loss of thefluid products therefrom in the event the struc- .ture of the well abovethe ground is subjected to damaging forces, including: valve meanspositioned in the well below said structure; said valve means beingspring loaded to occupy a position permitting flow through the well;said valve means being exposed to the pressure of fluid in the well andmovable responsive to said pressure into position to shut off said flow;means for subjecting said valve means to well fluid pressurecounteracting the well pressure tending to move said valve whereby thespring load will maintain the valve open; and control means operableresponsive to movement of the structure of the well above the ground forrelieving the valve means of said counteracting well pressure wherebysaid valve means will be moved by the well pressure into said position.

21. Apparatus for protecting a flowing well against the loss of fluidproducts from a flow conduit at the top of the well in the event thestructure of the well above the ground is subjected to potentiallydamaging forces, including: a flow conduit at the top of the well;subsurface valve means disposed in the well below said flow conduitincluding a body having a bore therein open to the well fluids, saidbody having a port leading from said bore through said body; a valvesleeve shiftable in opposite directions from an open to a closedposition to permit and prevent fluid flow through said port to the topof the well; said valve sleeve having opposed fluid pressure responsiveareas; one of said areas being exposed to fluid pressure in said borefor urging the sleeve to a closed position; means including a secondconduit leading from said subsurface valve means to the top of the welland connected to the flow conduit aforesaid for exposing the other ofsaid areas of said valve sleeve to well pressure to hold open saidsubsurface valve means; and control valve means at the .top of the wellconnected to one of said conduits and operable responsive to said forcesabove the ground for relieving said second conduit of well pressure,whereby said valve sleeve will be shifted by said fluid pressure in saidwell to a position closing said port.

22. Apparatus for protecting a flowing well against loss of fluidproducts from a flow conduit at the top of the well, including: a flowconduit at the top of the well; shiftable means at the top of the wellarranged to move under heavy forces accidentally applied at the top ofthe well before such forces become eflective to damage the flow conduitat the top of the well and cause such loss of fluid products; fluidpressure operated valve means disposed in the well below said flowstructure; said valve means including a body open to well fluids belowthe body and a passage communicating with said bore and extendingthrough the body; a valve element shiftable to positions opening andclosing said passage for permitting and preventing the flow of fluidproducts from the well; said valve element having a first fluid pressureresponsive area subjected to pressure of fluid in said well to shiftsaid element in a direction closing said passage; said valve elementhaving a second fluid pressure responsive area; means extending fromsaid valve means to the top of the well and connected to said flowconduit for subjecting said second fluid pressure responsive area ofsaid valve element to fluid pressure derived from the well for holdingsaid valve element in a position in which said passage is open; andcontrol valve means connected to said shiftable means at the top of thewell and operable by the latter upon the application of such potentiallydamaging forces to relieve said second fluid pressure responsive area ofsaid fluid pressure derived from the well, whereby said valve means willbe automatically closed.

23. Apparatus for protecting a flowing well against the loss of fluidproducts from a flow conduit at the top of the well, comprising: valvemeans disposed in the well below said flow conduit including a body opento well fluid below the body and having a passage extending through thebody; a valve element shiftable to positions opening and closing saidpassage; said element having a first fluid pressure responsive areasubjected to the pressure of fluid in said well for shifting said valveelement to a position closing said passage; said element having a secondfluid pressure responsive area; and means extending from said valvemeans and connected to said flow conduit for conducting fluid underpressure from the top of the well to said valve means so that wellpressure is imposed on said second fluid pressure responsive area toprevent said valve means from closing, whereby upon relief of the wellfluid pressure imposed on said second fluid pressure responsive areasaid valve means will be automatically closed.

24. A well tool including: a tubular body adapted to be positioned in awell conduit; means for sealing between said conduit and said body;means for supporting said body in said conduit; said body having a portabove said sealing means for conducting fluid from within said body intosaid conduit; a valve associated with said body for opening and closingsaid port; means for shifting said valve in opposite directions to openand close said port including first and second surfaces responsive tofluid pressure; means including a tube leading from the top of the wellfor conducting fluid to said first surface to open said port; saidsecond surface being exposed to well fluid pressure below said sealingmeans to close said port upon relief of the pressure applied to saidfirst surface; and valve means in said tube at the top of the well forcontrolling the application of fluid pressure through said tube to saidfirst surface to cause said valve to be held in a posi- 2% tion at whichsaid port is open and to allow said valve to be moved to a position atwhich said port is closed.

25 A well tool including: a tubular body adapted to be positioned in awell conduit; means for sealing between said conduit and said body;means for supporting said body in said conduit; said body having a portabove said sealing means for conducting fluid from within said body intosaid conduit; a valve associated with said body for opening and closingsaid port; means for shifting said valve in opposite directions to openand close said port including first and second surfaces responsive tofluid pressure; means including a tube leading from the top of the wellfor conducting fluid to said first surface to open said port; saidsecond surface being exposed to well fluid pressure below said sealingmeans to close said port upon relief of the pressure applied to saidfirst surface; and means at the top of the well for controlling theapplication of fluid pressure through said tube to said first surface tocause said valve to be held in a position at which said port is open andto allow said valve to be moved to a position at which said port isclosed.

26. A well tool as defined in claim 24, wherein the means forcontrolling the application of fluid pressure through said tubecomprises a valve.

27. A well tool as defined in claim 26, in which said valve is a manualvalve.

28. A well tool as defined in claim 26, wherein said valve comprisestrigger means operable responsive to a shock imposed on said means atthe top of the well.

29. A well tool including: a tubular body adapted to be anchored in awell; packing means on the body operable for sealing against the wall ofthe well; anchoring means on the body operable to anchor the tool in thewell; said body having a port above said packing means for conductingfluid from said body into the well above said body; a sleeve valveshiftably disposed in said body; means for shifting said sleeve valve inopposite directions to open and close said port including internal andexternal surfaces on said sleeve valve responsive to fluid pressure;said internal surface being exposed to well fluid pressure; meansincluding a conduit leading from the top of the well for conducting wellfluid pressure to said external valve sleeve surface; and means at thetop of the well and connected with said conduit for controlling theapplication of well pressure through said conduit to said externalsleeve valve surface to cause said port to be closed by said sleevevalve.

References Cited by the Examiner UNITED STATES PATENTS 2,963,089 12/60Sizer 166--224X FOREIGN PATENTS 774,784 5/57 Great Britain.

CHARLES E. OCONNELL, Primary Examiner.

1. APPARATUS FOR PROTECTING A FLOWING WELL AGAINST THE LOSS OF FLUIDPRODUCTS OF THE WELL FROM A CONDUIT AT THE TOP OF THE WELL, INCLUDING:MEANS AT THE TOP OF THE WELL ADAPTED TO BE MOVED BY FORCES WHICH IFSUSTAINED BY THE CONDUIT AT THE TOP OF THE WELL WOULD CAUSE SUCH LOSS;VALVE MEANS LOCATED IN THE WELL BELOW SAID FLOW STRUCTURE, SAID VALVEMEANS INCLUDING A BODY OPEN TO WELL FLUIDS THEREBELOW AND HAVING APASSAGE LEADING TO THE WELL ABOVE THE VALVE MEANS FROM SAID BODY; AVALVE ELEMENT IN SAID BODY SHIFTABLE TO A POSITION CLOSING SAID PASSAGETO CLOSE THE VALVE MEANS AND TO A POSITION SPACED FROM SAID PASSAGE